In an air conditioner in which plural outdoor units are connected to plural indoor units, at least one outdoor unit (1) is provided with a compressor (19) having a power control mechanism for inhibiting a part of a compression work, and the power of the compressor is made variable by controlling the power control mechanism (19b,19c). The outdoor unit (1) is provided with two heat exchangers (29,31) which are designed in a substantially U-shaped form, and disposed in a main body (10) of the outdoor unit so that the opening sides thereof are confronted to each other, and the refrigerating elements which constitutes a refrigerant circuit and contains at least the compressor (15,17,19), an accumulator (23), etc. are disposed in a space which is surrounded by the two heat exchangers.